[LTP] [PATCH v3 4/4] Simplify ioctl02.c further

Martin Doucha mdoucha@suse.cz
Fri Sep 15 17:11:56 CEST 2023


Hi,
please merge this patch with patch 1 and also merge patch 2 with patch 3.

On 07. 09. 23 17:51, Marius Kittler wrote:
> * Use checkpoint API instead of signals
> * Use SAFE_…-macros instead of manual error handling
> 
> Signed-off-by: Marius Kittler <mkittler@suse.de>
> ---
>   testcases/kernel/syscalls/ioctl/ioctl02.c | 167 ++++++----------------
>   1 file changed, 43 insertions(+), 124 deletions(-)
> 
> diff --git a/testcases/kernel/syscalls/ioctl/ioctl02.c b/testcases/kernel/syscalls/ioctl/ioctl02.c
> index 6b0924c65..30c647ca3 100644
> --- a/testcases/kernel/syscalls/ioctl/ioctl02.c
> +++ b/testcases/kernel/syscalls/ioctl/ioctl02.c
> @@ -13,50 +13,49 @@
>    *
>    *	In this test, the parent and child open the parentty and the childtty
>    *	respectively.  After opening the childtty the child flushes the stream
> - *	and sends a SIGUSR1 to the parent (thereby asking it to continue its
> - *	testing). The parent, which was waiting for this signal to arrive, now
> - *	starts the testing. It issues a TCGETA ioctl to get all the tty
> - *	parameters. It then changes them to known values by issuing a TCSETA
> - *	ioctl.  Then the parent issues a TCGETA ioctl again and compares the
> - *	received values with what it had set earlier. The test fails if TCGETA
> - *	or TCSETA fails, or if the received values don't match those that were
> - *	set. The parent does all the testing, the requirement of the child
> - *	process is to moniter the testing done by the parent, and hence the
> - *	child just waits for the parent.
> + *	and sends a wakes the parent (thereby asking it to continue its
> + *	testing). The parent, then starts the testing. It issues a TCGETA
> + *	ioctl to get all the tty parameters. It then changes them to known
> + *	values by issuing a TCSETA ioctl. Then the parent issues a TCGETA
> + *	ioctl again and compares the received values with what it had set
> + *	earlier. The test fails if TCGETA or TCSETA fails, or if the received
> + *	values don't match those that were set. The parent does all the
> + *	testing, the requirement of the child process is to moniter the
> + *	testing done by the parent, and hence the child just waits for the
> + *	parent.
>    */
>   
>   #include <stdio.h>
>   #include <fcntl.h>
> -#include <signal.h>
>   #include <errno.h>
>   #include <sys/wait.h>
>   #include <sys/types.h>
>   #include <sys/stat.h>
>   #include <termios.h>
> +
> +#include "tst_checkpoint.h"
>   #include "tst_test.h"
>   #include "tst_safe_macros.h"
>   
> -#define	CNUL	0
> -
>   static struct termio termio, save_io;
>   
>   static char *parenttty, *childtty;
>   static int parentfd = -1, childfd = -1;
>   static int parentpid, childpid;
> -static volatile int sigterm, sigusr1, sigusr2;
>   
>   static int do_child_setup(void);
> -static int do_parent_setup(void);
>   static int run_ptest(void);
>   static int run_ctest(void);
>   static int chk_tty_parms();
>   static void setup(void);
>   static void cleanup(void);
>   static void do_child(void);
> -static void sigterm_handler(void);
>   
>   static char *device;
>   
> +static const int checkpoint_child_ready = 1;
> +static const int checkpoint_parent_done_testing = 2;
> +
>   static void verify_ioctl(void)
>   {
>   	parenttty = device;
> @@ -67,28 +66,21 @@ static void verify_ioctl(void)
>   	if (childpid == 0)
>   		do_child();
>   
> -	while (!sigusr1)
> -		sleep(1);
> +	TST_CHECKPOINT_WAIT(checkpoint_child_ready);
>   
> -	sigusr1 = 0;
> -
> -	parentfd = do_parent_setup();
> -	if (parentfd < 0) {
> -		kill(childpid, SIGTERM);
> -		waitpid(childpid, NULL, 0);
> -		cleanup();
> -	}
> +	parentfd = SAFE_OPEN(parenttty, O_RDWR, 0777);
> +	/* flush tty queues to remove old output */
> +	SAFE_IOCTL(parentfd, TCFLSH, 2);
>   
>   	/* run the parent test */
>   	int rval = run_ptest();
>   	if (rval == -1) {

This error handling branch is now identical to normal child wakeup so it 
can be removed.

>   		/*
>   		 * Parent cannot set/get ioctl parameters.
> -		 * SIGTERM the child and cleanup.
> +		 * wake the child and cleanup.
>   		 */
> -		kill(childpid, SIGTERM);
> +		TST_CHECKPOINT_WAKE(checkpoint_parent_done_testing);
>   		waitpid(childpid, NULL, 0);
> -		cleanup();
>   	}
>   
>   	if (rval != 0)
> @@ -97,17 +89,15 @@ static void verify_ioctl(void)
>   	else
>   		tst_res(TPASS, "TCGETA/TCSETA tests SUCCEEDED");
>   
> -	/* FIXME: check return codes. */
> -	(void)kill(childpid, SIGTERM);
> -	(void)waitpid(childpid, NULL, 0);
> +	TST_CHECKPOINT_WAKE(checkpoint_parent_done_testing);
> +	waitpid(childpid, NULL, 0);

waitpid() is unnecessary unless you want to check child exit status. The 
child process will be reaped by the LTP library automatically.

>   
>   	/*
>   	 * Clean up things from the parent by restoring the
>   	 * tty device information that was saved in setup()
>   	 * and closing the tty file descriptor.
>   	 */
> -	if (ioctl(parentfd, TCSETA, &save_io) == -1)
> -		tst_res(TINFO, "ioctl restore failed in main");
> +	SAFE_IOCTL(parentfd, TCSETA, &save_io);
>   	SAFE_CLOSE(parentfd);

This will be done by cleanup() automatically.

>   }
>   
> @@ -151,32 +141,18 @@ static int run_ptest(void)
>   	/* Set output modes. */
>   	termio.c_oflag = OPOST | OLCUC | ONLCR | ONOCR;
>   
> -	TEST(ioctl(parentfd, TCSETA, &termio));
> +	SAFE_IOCTL(parentfd, TCSETA, &termio);
>   
>   	/* Get termio and see if all parameters actually got set */
> -	int rval = ioctl(parentfd, TCGETA, &termio);
> -	if (rval < 0) {
> -		tst_res(TFAIL, "ioctl TCGETA failed.  Ending test.");
> -		return -1;
> -	}
> -
> +	SAFE_IOCTL(parentfd, TCGETA, &termio);
>   	return chk_tty_parms();
>   }
>   
>   static int run_ctest(void)
>   {
> -	/*
> -	 * Wait till the parent has finished testing.
> -	 */
> -	while (!sigterm)
> -		sleep(1);
> -
> -	sigterm = 0;
> -
> -	tst_res(TINFO, "child: Got SIGTERM from parent.");
> -
> -	if (close(childfd) == -1)
> -		tst_res(TINFO, "close() in run_ctest() failed");
> +	TST_CHECKPOINT_WAIT(checkpoint_parent_done_testing);
> +	tst_res(TINFO, "child: parent has finished testing");
> +	SAFE_CLOSE(childfd);
>   	return 0;
>   }
>   
> @@ -206,12 +182,11 @@ static int chk_tty_parms(void)
>   
>   	for (i = 0; i < NCC; i++) {
>   		if (i == VEOL2) {
> -			if (termio.c_cc[VEOL2] == CNUL) {
> +			if (!termio.c_cc[VEOL2]) {
>   				continue;
>   			} else {
>   				tst_res(TINFO, "control char %d has "
> -					 "incorrect value %d %d", i,
> -					 termio.c_cc[i], CNUL);
> +					 "incorrect value %d", i, termio.c_cc[i]);
>   				flag++;
>   				continue;
>   			}
> @@ -250,110 +225,54 @@ static int chk_tty_parms(void)
>   	return flag;
>   }
>   
> -static int do_parent_setup(void)
> -{
> -	int pfd = SAFE_OPEN(parenttty, O_RDWR, 0777);
> -
> -	/* flush tty queues to remove old output */
> -	SAFE_IOCTL(pfd, TCFLSH, 2);
> -	return pfd;
> -}
> -
>   static int do_child_setup(void)
>   {
> -	int cfd;
> -
> -	cfd = open(childtty, O_RDWR, 0777);
> +	int cfd = SAFE_OPEN(childtty, O_RDWR, 0777);
>   	if (cfd < 0) {
> -		tst_res(TINFO, "Could not open %s in do_child_setup(), errno "
> -			 "= %d", childtty, errno);
> -		/* signal the parent so we don't hang the test */
> -		kill(parentpid, SIGUSR1);
> +		/* wake the parent so we don't hang the test */
> +		TST_CHECKPOINT_WAKE(checkpoint_child_ready);

This wake call is unreachable. The parent should use wait with timeout 
in case the child fails to open the TTY.

>   		return -1;
>   	}
>   
>   	/* flush tty queues to remove old output */
> -	if (ioctl(cfd, TCFLSH, 2) < 0) {
> -		tst_res(TINFO, "ioctl TCFLSH failed. : errno = %d", errno);
> -		/* signal the parent so we don't hang the test */
> -		kill(parentpid, SIGUSR1);
> +	if (SAFE_IOCTL(cfd, TCFLSH, 2) < 0) {
> +		/* wake the parent so we don't hang the test */
> +		TST_CHECKPOINT_WAKE(checkpoint_child_ready);

Again, unreachable wake call.

>   		return -1;
>   	}
>   
>   	/* tell the parent that we're done */
> -	kill(parentpid, SIGUSR1);
> +	TST_CHECKPOINT_WAKE(checkpoint_child_ready);
>   
>   	return cfd;
>   }
>   
> -/*
> - * Define the signals handlers here.
> - */
> -static void sigterm_handler(void)
> -{
> -	sigterm = 1;
> -}
> -
> -static void sigusr1_handler(void)
> -{
> -	sigusr1 = 1;
> -}
> -
> -static void sigusr2_handler(void)
> -{
> -	sigusr2 = 1;
> -}
> -
>   static void setup(void)
>   {
>   	if (!device)
>   		tst_brk(TBROK, "You must specify a tty device with -D option");
>   
> -	int fd;
> -	struct sigaction act;
> -
>   	/* XXX: TERRNO required all over the place */
> -	fd = SAFE_OPEN(device, O_RDWR, 0777);
> +	int fd = SAFE_OPEN(device, O_RDWR, 0777);
>   
>   	/* Save the current device information - to be restored in cleanup() */
>   	SAFE_IOCTL(fd, TCGETA, &save_io);
>   
>   	/* Close the device */
>   	SAFE_CLOSE(fd);
> -
> -	/* Set up the signal handlers */
> -	act.sa_handler = (void *)sigterm_handler;
> -	act.sa_flags = 0;
> -	sigemptyset(&act.sa_mask);
> -	(void)sigaction(SIGTERM, &act, 0);
> -
> -	act.sa_handler = (void *)sigusr1_handler;
> -	act.sa_flags = 0;
> -	(void)sigaction(SIGUSR1, &act, 0);
> -
> -	act.sa_handler = (void *)sigusr2_handler;
> -	act.sa_flags = 0;
> -	(void)sigaction(SIGUSR2, &act, 0);
> -
> -	act.sa_handler = SIG_IGN;
> -	act.sa_flags = 0;
> -	(void)sigaction(SIGTTOU, &act, 0);
> -
> -	sigterm = sigusr1 = sigusr2 = 0;
>   }
>   
>   static void cleanup(void)
>   {
> -	if (parentfd != -1) {
> -		if (ioctl(parentfd, TCSETA, &save_io) == -1)
> -			tst_res(TINFO, "ioctl restore failed in cleanup()");
> -		if (close(parentfd) == -1)
> -			tst_res(TINFO, "close() failed in cleanup()");
> +	if (parentfd >= 0) {
> +		SAFE_IOCTL(parentfd, TCSETA, &save_io);
> +		SAFE_CLOSE(parentfd);
>   	}
>   }
>   
>   static struct tst_test test = {
>   	.needs_root = 1,
> +	.needs_checkpoints = 1,
>   	.forks_child = 1,
>   	.setup = setup,
>   	.cleanup = cleanup,

-- 
Martin Doucha   mdoucha@suse.cz
SW Quality Engineer
SUSE LINUX, s.r.o.
CORSO IIa
Krizikova 148/34
186 00 Prague 8
Czech Republic



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